1. Field of the Invention
This invention relates generally to a method and apparatus for producing sheets of corrugated cardboard with a variable format.
2. Description of the Related Art
It is known to provide a corrugated cardboard installation in which the web of corrugated cardboard is removed from a heating and pulling device at a predetermined operating speed and is divided across the entire width of the web by a cross cutter when the format of the corrugated cardboard sheets that are to be produced is changed. The remaining web for a certain number of sheets in a lot is then accelerated and the new web of cardboard arriving from the heating and pulling device is slowed down, thus resulting in a gap between the remaining web leaving the machine and the new web coming in. During this gap in the cardboard web, the longitudinal cutting and grooving device and cross cutter are reset for the new format. A disadvantage of this arrangement is that the remaining web leaving the machine and the new web arriving in the direction of conveyance are not subjected to tension and therefore are not guided adequately. This results in cutting differences on the cross cutter and cutting and grooving differences on the longitudinal cutting and grooving device. This results in unnecessarily large volumes of waste and in some cases, break-downs in operations. This is especially problematical with corrugated cardboard webs that are preprinted and must be cut with high precision. Furthermore, the working speed must be varied in order to form the gap.